scholarly journals The synthetic triterpenoid, RTA 405, increases the glomerular filtration rate and reduces angiotensin II–induced contraction of glomerular mesangial cells

2013 ◽  
Vol 83 (5) ◽  
pp. 845-854 ◽  
Author(s):  
Yanfeng Ding ◽  
Rhesa D. Stidham ◽  
Ron Bumeister ◽  
Isaac Trevino ◽  
Ali Winters ◽  
...  
2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Weizu Li ◽  
Yanfeng Ding ◽  
Crystal Smedley ◽  
Yanxia Wang ◽  
Sarika Chaudhari ◽  
...  

1988 ◽  
Vol 255 (3) ◽  
pp. F545-F551
Author(s):  
H. M. Siragy ◽  
N. E. Lamb ◽  
C. E. Rose ◽  
M. J. Peach ◽  
R. M. Carey

The mechanism by which atrial natriuretic peptide (ANP) increases renal water and solute excretion is not fully understood. We studied the renal effects of ANP and angiotensin II (ANG II) separately and together in uninephrectomized conscious dogs (n = 7) in sodium metabolic balance (80 meq/day). Exogenous ANG II and ANP were without measurable systemic effects as demonstrated by absence of changes in blood pressure, plasma aldosterone concentration, and plasma renin activity. The quantity of ANG II that had significant renal effects that were without measurable systemic effects was 0.2 pmol.kg-1.min-1. Three infusion rates of ANP had significant renal effects (1, 10, and 20 pmol.kg-1.min-1). These quantities of ANP caused significant diuresis, natriuresis, kaliuresis, and increased glomerular filtration rate without significant changes in renal plasma flow. ANG II alone caused significant antidiuresis, antinatriuresis, and decreased glomerular filtration rate and renal plasma flow. When ANG II and ANP were given together, no change in urinary flow rate, urinary sodium or potassium excretion, or renal plasma flow was observed, whereas glomerular filtration rate increased. Filtration fraction increased significantly with ANG II and ANP separately and together. Intrarenal ANP prevents the ANG II-induced decrement in urinary sodium excretion and urine flow rate. ANP may play an important role in escape from the sodium-retaining action of intrarenal ANG II.


1991 ◽  
Vol 80 (2) ◽  
pp. 143-147 ◽  
Author(s):  
Luis M. Villamediana ◽  
Mercedes Velo ◽  
Ana Olivera ◽  
Luis Hernando ◽  
Carlos Caramelo ◽  
...  

1. The effects of angiotensin II on glomerular filtration rate and renal plasma flow were studied in surgically instrumented conscious control and cirrhotic rats. In addition, angiotensin II binding and the contractile response to angiotensin II were studied in glomeruli isolated from cirrhotic and control rats. 2. Cirrhotic rats had a higher glomerular filtration rate and a higher renal plasma flow than control animals. A non-pressor dose of angiotensin II induced small but significant decreases in glomerular filtration rate and renal plasma flow in both control and cirrhotic rats, the effect on renal plasma flow being the most pronounced. 3. Plasma renin and aldosterone concentrations were similar in control and cirrhotic rats. 4. The cross-sectional area of glomeruli from cirrhotic rats was 42% greater than that of glomeruli from control animals. Angiotensin II (10−9 mol/l) decreased the cross-sectional area of glomeruli from control animals by 6.4 ± 0.9% and of glomeruli from cirrhotic rats by 6.6 ± 0.8% (P = not significant for comparison between control and cirrhotic animals). 5. There were no differences between control and cirrhotic rats in the affinity of angiotensin II for its glomerular receptors. However, the angiotensin II receptor density was higher in cirrhotic than in control rats, thereby producing an increased total angiotensin II binding in cirrhotic rats. 6. Since no functional differences between control and cirrhotic animals were present in the response to angiotensin II, even though angiotensin II binding was increased, a post-receptor blockade of the angiotensin II signal could be present in cirrhotic rats.


1971 ◽  
Vol 49 (6) ◽  
pp. 608-612 ◽  
Author(s):  
D. Regoli ◽  
R. Gauthier

Angiotensin II, angiotensin I, adrenaline, or noradrenaline was infused in rabbit kidneys isolated and perfused with oxygenated Krebs solution. Adrenaline increased the perfusion pressure and slightly decreased the filtration fraction and the glomerular filtration rate. Angiotensins had similar effects on the perfusion pressure, but significantly increased filtration fraction and glomerular filtration rate.It is suggested that adrenaline acts on the afferent, while angiotensins II and I constrict the efferent, glomerular artery.


1976 ◽  
Vol 230 (5) ◽  
pp. 1187-1193 ◽  
Author(s):  
M Beaufils ◽  
J Sraer ◽  
C Lepreux ◽  
R Ardaillou

125I-labeled angiotensin II (125I-labeled AII) and [3H]angiotensin II ([3H]AII) bind specifically to isolated rat glomeruli. Three groups of receptor sites could be defined by the KD value (7.1 +/- 0.3 X 10(-11, 3.4 +/- 0.2 X 10(-10), and 1.6 X 10(-9) M, respectively) and the number of receptor sites (11.6 +/- 1.2, 29.4 +/- 3.9, and 113.8 +/- 3.8 fmol/mg glomerular protein, respectively). Both association and dissociation constants for 125I-labeled AII were greater than those for [3H]AII, but their ratio (KD) remained unchanged. Specificity of binding to these three groups of receptor sites was demonstrated by the following: 1) inhibition of binding of labeled AII by unlabeled hormone or by antagonists; and 2) reversibility of binding, independent of either hormone or receptor degradation. Binding was increased in glomerular preparations from acutely and chronically sodium-loaded rats, compared with glomerular preparations from acutely and chronically sodium-depleted rats. This change in binding resulted from both a change in the number of receptor sites and modification of the affinity of AII for its receptors. KD was higher in preparations from sodium-depleted rats (12.9 +/- 3.3 and 14.6 +/- 3.9 X 10(-11) M in chronically and acutely depleted rats, respectively) than in those from sodium-loaded rats (2.7 +/- 0.2 and 3.9 +/- 1 X 10(-11) M in chronically and acutely sodium-loaded rats, respectively). Changes in the binding of AII to its glomerular receptors could play a role in the adaptation of glomerular filtration rate to the sodium balance.


1997 ◽  
Vol 16 (3) ◽  
pp. 347-355
Author(s):  
Winthrop J. Harewood ◽  
Annemarie Hennessy ◽  
Geoffrey G. Duggin ◽  
John S. Horvath ◽  
David J. Tiller

1991 ◽  
Vol 81 (s25) ◽  
pp. 457-464 ◽  
Author(s):  
T. Hannedouche ◽  
M. Lazaro ◽  
A. G. Delgado ◽  
C. Boitard ◽  
B. Lacour ◽  
...  

1. A sustained high glomerular filtration rate in diabetes mellitus is associated with increased proximal reabsorption, suggesting alterations in the tubulo-glomerular feedback system. To test this hypothesis, renal function was studied in eight control subjects and 14 recent-onset euglycaemic insulin-dependent diabetic patients before and after infusion of the carbonic anhydrase inhibitor, acetazolamide (5 mg/kg body weight). 2. Acetazolamide induced a dramatic fall in glomerular filtration rate in both diabetic patients and control subjects (from 138 ± 5 to 114 ± 4 and from 127 ± 3 to 113 ± 2 ml min−1 1.73 m−2, respectively, P < 0.0001). This fall in glomerular filtration rate was strongly correlated with the acetazolamide-induced decrease in absolute proximal reabsorption calculated by using lithium clearance. 3. To further assess the potential role of angiotensin II in the acetazolamide-induced tubulo-glomerular feedback response, 11 additional diabetic patients were investigated before and after the administration of acetazolamide plus the angiotensin-converting enzyme inhibitor, enalaprilat (1.25 mg intravenously). Despite the effective blockade of angiotensin II formation and a slight decrease in renal vascular resistance, the glomerular filtration rate fell significantly and by a similar magnitude as seen with acetazolamide alone. 4. These results indirectly suggest that there is an altered basal tubulo-glomerular feedback system in diabetic patients but a normal response to the increase in distal delivery. No convincing role for an angiotensin II-mediated effect on the afferent limb of the tubulo-glomerular feedback response could be demonstrated.


2013 ◽  
Vol 304 (7) ◽  
pp. F900-F907 ◽  
Author(s):  
Norma B. Ojeda ◽  
Thomas P. Royals ◽  
Barbara T. Alexander

This study tested the hypothesis that Rho kinase contributes to the enhanced pressor response to acute angiotensin II in intact male growth-restricted and gonadectomized female growth-restricted rats. Mean arterial pressure (MAP) and renal function were determined in conscious animals pretreated with enalapril (250 mg/l in drinking water) for 1 wk to block the endogenous renin-angiotensin system and normalize blood pressure (baseline). Blood pressure and renal hemodynamics did not differ at baseline. Acute Ang II (100 ng·kg−1·min−1) induced a greater increase in MAP and renal vascular resistance and enhanced reduction in glomerular filtration rate in intact male growth-restricted rats compared with intact male controls ( P < 0.05). Cotreatment with the Rho kinase inhibitor fasudil (33 μg·kg−1·min−1) significantly attenuated these hemodynamic changes ( P < 0.05), but it did not abolish the differential increase in blood pressure above baseline, suggesting that the impact of intrauterine growth restriction on blood pressure in intact male growth-restricted rats is independent of Rho kinase. Gonadectomy in conjunction with fasudil returned blood pressure back to baseline in male growth-restricted rats, and yet glomerular filtration rate remained significantly reduced ( P < 0.05). Thus, these data suggest a role for enhanced renal sensitivity to acute Ang II in the developmental programming of hypertension in male growth-restricted rats. However, inhibition of Rho kinase had no effect on the basal or enhanced increase in blood pressure induced by acute Ang II in the gonadectomized female growth-restricted rat. Therefore, these studies suggest that Rho kinase inhibition exerts a sex-specific effect on blood pressure sensitivity to acute Ang II in growth-restricted rats.


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